Steam iron



me. 21, 1943. E. O. MORTON STEAM IRON Filed April 11, 1942 s4 as as .u

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-INVEN TOR EL. can 0. Mom-0N ATTORi Patented Dec. 21, 1 943 STEAM IRONEldred 0. Morton, Mansfield, Ohio, assignor to Westinghouse El ctric &Manufacturing Company, East Pittsburgh, Pa., a corporation ofPennsylvania Application April 11, 1942, Serial No. 438,537

Claims.

This invention relates to steam pressing irons and particularly to thatclassof steam irons which include a valve-controlled water supply forfeeding water at a selected rate to a steam generator provided in theiron, and it has for an object to provide an improved steam iron of thecharacter set forth.

In testing steam pressing irons oi. the flashboiler type, wherein wateris supplied from a storage chamber carried by the iron to a steam'generator which instantaneously flashes the water into steam. I havefound that there is a tendency for the flow of steam from the steamgenerator to decrease as the temperature of the water within the storagechamber rises, indicating that the flow of water to the steam generatordecreases, during a prolonged period of use of the iron. This result maybe partially due to the decrease in head of the water in the chamber asthe supply is depleted and it may also be due to some vaporization ofthe water in the passage between the chamber and the steam generatorwhich tends to restrict the flow of water through the passage. I havealso found that this condition can be corrected by increasing the valveopening as the temperature of the water in the storage chamber rises,without materially increasing the rate ofsteam flow from the generatorto the material being ironed. While in making this correction, it ispossible that the valve opening may be increased to a point where itadmits more water to the steam generator, a slight increase in waterflow is not objectionable when the water is hot because the evaporatingcapacity of the steam generator is increased by the amount of heatabsorbed by the water in the storage chamber..

In accordance with my invention, I provide a self-compensating valvewhich automatically increases the valve opening as the temperature ofthe water within the storage chamber rises to insure that suflicientwater enters the steam generator regardless of conditions which tend toreduce the rate of flow of water to the steam generator. It is to beunderstood that if it be found that the valve opening should be reducedin size as the temperature of the water in the storage chamberincreases, theautomatic compensation obtained with my; invention may besuch as to decrease the size of the valve opening with a rise in thetemperature of the water in the storage chamber. A reduction in the sizeof the valve opening with an increase in water temperature may berequired if the decrease in viscosity in the water tends to increase therate of flow through the valve.

It is an object of my invention to provide a construct on of steam ironin which the valve which controls the rate of water flow to the steamgenerator is automatically adjusted in accordance with temperatureconditions in the iron.

It is another object of my invention to provide a steam ironconstruction in which th assembly of the iron and alignment of the waterflow regulating means are facilitated.

These and other objects are effected by my invention as will be apparentfrom the following description and claims taken in accordance with theaccompanying drawing, forming a part of this application, in which:

Fig. 1 is a side elevational view, partially in longitudinal section, ofan electrically-heated steam iron in which the present invention hasbeen incorporated;

Fig. 2 is a horizontal sectional view of the steam iron shown in Fig. 1and taken substantially on the line IIII of that figure; and,

Fig. 3 is a fragmentary sectional view corresponding to a portion ofFig. 1 illustrating a slightly modified form of the invention.

Referring to the drawing, there has been shown an electrically-heatedsteam iron, generally indicated l0, which comprises a soleplate H, acover member l2, and a handle l3 secured together in any suitablemanner.

The soleplate maybe heated in any desired manner and is here shown ashaving a U-shaped,

armored electric heating element l4 embedded therein, which is adaptedto be connected to a source of electrical energy by means of supplyconductors IS. The temperature at which the soleplate is to bemaintained is selected by means of a knob l6 which adjusts a thermostatI! mounted within a recess in the soleplate and connected in series withthe heating element M. The

' knob I6 is provided with the usual index or scale,

and is operatively connected to the thermostat by means of a rod l8.This rod extends through a sleeve l9 brazed or otherwise secured influidtight relation to the top wall 20 of the cover member l2 and alower horizontal partition 2 I.

As shown particularly in Fig. 1, a liquid-storage chamber 22 is formedwithin the cover l2 by means of the horizontal partition M and avertical partition 23 which, together with the side and top walls of thecover, define an enclosed space. The storage chamber 22 isfilled withwateror other vaporizable liquid suitable for dampening clothes throughan opening provided into the steam generator.

in the top wall of the cover, which opening is normally closed by meansof a removable cap or plug 24. If desired, a vent (not shown) may beprovided for thestorage chamber 22.

The water within the storage chamber is fed, in a manner to behereinafter described, to a steam generator provided in the soleplate.The steam generator comprises a steam-generating space formed by a recesor hole in the soleplate located within the loop or bight 26 of theheating element l4. This recess opens on the ironing surface 21 of thesoleplate and is closed at its lower end by means of a removablemetallic member or plug 28 which is threaded or otherwise removablysecured to the soleplate in spaced relation to the upper wall 29 of thesoleplate overlying the recess 25.

The upper surface of this plug is provided with an annular rib or baffle3| which divides the space between the plug 28 and wall 29 into twocommunicating compartments 32 and 33. The rib 3| provides a pocket inwhich the water from the storage chamber 22 is received and instantlyflashed into steam, the steam thus formed passing over the rib into theannular compartment 33. The steam is then discharged from ports 34,preferably formed in the plug, to the material t be pressed.

A tubular strut 35 is fixed in fluidtight relation to the upper andlower-wall 20 and 2| of the storage chamber above the steam generator,as by brazing or the like, This strut, as shown in Fig. 1, extends belowthe lower wall 2| of the storage chamberand is provided with a reducedexternally-threaded lower end- 36 which is received in an aperture inthe upper wall 29 of the soleplate. A nut 31 threaded on this reducedend serves to clamp the strut to the soleplate in fluidtight relation.as will be apparent from Fig. l. The upper end of the strut isinternally threaded and receives a threaded bushing 38. This bushingadjustably receives a threaded portion of a valve stem 39. The strut isalso provided with a valve stem guide 40 which aids in maintaining thevalve stem in alignment in the strut.

The upper end of this valve stem is provided with a knob 4| which isrotated to raise or lower the valve stem in the bushing 38 and adjustthe valve stem with respect to a valve seat 42 which is formed in orfixed relative to the lower end of the strut 35. The lower end of thisvalve stem is provided with a tapered point 43 'which cooperates withthe valve seat 42 for regulating or throttling the flow of water throughthe valve The lower end of the valve stem is provided with a secondtapered portion 44 spaced above the tapered point which is adapted toengage the valve seat 42 to close th valve when it is desired to shutoff the supply of water to the steam generator. The particular valvestem and valve seat disclosed is like that coefficient of expansion,such as aluminum, and the valve stem of a material having a lowcoefficient of expansion, such as invar, the tapered chamber increases,the valve stem may be made of a material having a high coefficient ofexpansion and the strut made of a material having a low coefiicient ofexpansion to automatically reduce the size of the Valve opening with anincrease of temperature of the strut and valve stem.

The strut, in addition to the function of cooperating with the valvestem to obtain automatic valve opening adjustment, also serves torigidly tie the upper and lower walls of the reservoir together andthereby minimize the tendency of these parts to buckle when heated. Thestructure described has a further advantage in that alignment of thevalve stem and its tapered lower end with respect to the valve seat issimplified in that the valve seat and the valve stem are carried by thestrut which may be of substantial weight as compared to the relativelylight construction of the cover structure.

Operwtion To use the present iron, the operator connects the conductorsl5 to a suitable source of electricity and adjusts the thermostat H, bymeans or the knob Hi, to maintain the soleplate atany desiredtemperature. It is assumed that the storage chamber 22 has been filledwith water or other vaporizable liquid suitable for dampening thematerial to be pressed. When the soleplate has reached ironingtemperature, the iron may be used as a dry iron or if it is desired tosteam the material while pressing, the operator turns the knob 4| toopen the water valve and permit water to flow into the team generator ata predetermined rate. The knob 4| may be provided with a suitable scaleto indicate the rate of water flow to the steam generator for theparticular setting thereof. It will be understood that the valve stemmay be actuated as a sliding plunger rather than as a rotatable shafthaving threaded engagement with the upper end of the strut, as shown forexample in my copending application, Serial No. 394,258, filed May 20,1941, and assigned to the assignce of the present invention. If thevalve stem is adjusted by sliding the same up or down relative to thevalve seat it may be held in fixed relation to the upper end of thestrut during normal use of the iron in any suitdescribed and claimed inmy copending application Serial No. 405.463, filed August 5, 1941, andassigned to the assignee of the present application.

The strut 35 and valve stem 39 are made ,of materials havingsubstantially different coefficients of expansion so that as thetemperature of these, parts rises, due to an increase in temperature ofthe water within the storage chainber and from the heat conducted fromthe soleplate directly through the metal, the lower end of the valvestem and the valve seat will have relative movement with respect toeach'othpr. By making the strut of a material having a men able manneras by having a friction fit in the bushing member 38. I

The water in the storage chamber passes through openings 45 provided inthe strut 35, through the open valve into a passage 46 provided throughthe lower reduced end of the strut from which it falls into thesteam-generating chamber 32 where it is instantaneously flashed intosteam. The steam thus formed is carried over the rib 3| -to the steamoutlet ports 34 from which it is discharged to the material beingpressed.

While the storage chamber is preferably thermally insulated from theheated soleplate, as by an air space 41, it will be appreciated that thetemperature of the water stored in the storage chamber will rise duringprolonged use of the iron and may even reach the boiling point. Thevalve stem and the strut are in intimate contact with the water in thestorage chamber and the temperature thereof also rises. Since the valvestem and strut are made of materials having substantially difierentcoefllcients of expansion, the lower free end of the valve'stem and thevalve seat carried by the lower end of the strut will move relative toeach other as the temperature of the strut and .valve stem rise sincethe stem and strut are interconnected at the'upper end of the strut.Thus, in the particular iron illustrated, an increase in the temperatureof the strut and the valve stem will cause the lower tapered end of thevalve stem to be raised relative to the valve seat to increase the valveopening. By reversing the materials of these parts, that is, making thevalve stem of material having a high coeificient of expansion and thestrut of low coeflicient of expansion material, an increase intemperature of these parts would result in a reduction of the size ofthe valve opening.

If desired, the valve seat 42 may be formed in a member 49 separate fromthe strut 35 as shown in Fig. 3. Further, this member may be made ofharder and more durable material than the strut proper to reduce wear ofthe valve seat. The member 49 is provided with a flange or head portionwhich engages the undersurface of the wall 29 of the soleplate and isscrew-threaded into the lower end of the strut 35 which engages the topsurface of the wall 29 to clamp the strut in fluid-tight relation to thesoleplate.

While I have shown my invention in several forms, it will be obvious tothose skilled in the art that it is not so limited, but is susceptibleof various other changes and modifications without departing from thespirit thereof, and I desire,

therefore, that only such limitations shall be placed thereupon asarespecifically set forth in the appended claims.

What I claim is:

through, means for supporting said valve seat, said supporting meansbeing adjustably connected to said valve member at a point spaced asubstantial distance from said valve seat, said supporting means andsaid valve member-being made of materials having substantially differentcoefficients of expansion and so arranged in said iron as to be afiectedby the temperature of the watersupplied to said steam generator andadapted 1. A steam iron comprising a body portion having a steamgenerator, means for heating said steam generator, means including aconduit opening into said steam generator for supplying water to saidsteam generator, said means also including a valve seat and a valvemember cooperating with said valve seat to regulate the flow of waterthrough said conduit to said steam generator to provide a predeterminedrate of flow of water, means fixed relative to said valve seat andconnected to said valve member a substantial distance from said valveseat, said last-mentioned means and said valve member being made ofmaterials having substantially different .coefficients of expansion andso arranged in said iron as to be affected by the temperature of thewater supplied to said steam generator and adapted upon a change intemperature of said valve member and said last-mentioned means to causerelative movement between said valve member and valve seat in thedirection and in such amount as to substantially reduce deviation fromsaid predetermined rate of flow.

2. A steam iron comprising a soleplate, means for heating saidsoleplate, a steam generator car-' ried by said soleplate, meansincluding a conduit opening into-said steam generator for supplyingwater to said steam generator, an adjustable valve for regulating theflow of water through said conduit, said valve including a valve seatand a valve member adjustable relative to said seat to provide aselected rate of flow of water thereupon a change in temperature of saidsupporting means and said valve member to provide relative movementbetween said valve seat and said valve member to change the size of theopening through said valve in the direction and in such amount as tosubstantially reduce deviation from said selected rate of flow.

3. A steam iron comprising a soleplate, means for heating saidsoleplate, a steam generator carried by said soleplate, a liquid-storagechamber carried by said soleplate, a passage for conveying liquid fromsaid chamber to said steam generator, a valve seat formed in saidpassage, a valve stem extending through said storage chamber andcooperating with said valve seat to control the flow of liquid from saidchamber to said steam generator, a strut extending through said chamberand engaging said valve stem at one end thereof, said valve seat beingfixed relative to the other end of said strut, means for adjusting saidvalve stem relative to said strut and valve seat to provide apredetermined rate of flow to the steam generator, said strut and saidvalve stem being made of materials having substantially differentcoefiicientsof expansion and adapted upon a rise in temperature of saidstrut and said valve stem to cause relative movement between said valvestem and said valve seat in the direction to increase the openingbetween said valve seat and stem in such amount as to substantiallyreduce deviation from said predetermined rate of flow.

a. A steam iron comprising a body having a liquid-storagechamber, asteam generator carried by said body, said storage chamber comprisingspaced upper and lower walls of light-weight sheet material, a rigidstrut extending between and connected to said walls, said lower wallhaving a passage therethrough communicating with said steam generatorand located adjacent the lower end of said strut, a valve seat providedin said passage and fixed relative to said strut, a.

valve stem adapted to cooperate with said valve seat for regulating theflow of liquid through said coeflicients of expansion and adapted upon achange in temperature of said stem and strut to cause said valve stemand valve seat to be moved relative to each other to vary the size ofthe opening between said stem and valve seat in the direction and insuch amount as to substantially reduce deviation from said selected rateof flow.

5. A steam iron comprising a body having a liquid-storage chamber, asteam generator carried by said body, a passage for conveying liquidfrom said chamber to said steam generator, said storage chamber havingupper and lower walls formed of light-weight sheet material, a vertical,perforate tubular strut extending between and connected to said upperand lower walls, said passage having a valve seat therein fixed relativeto'the lower end of said strut, a valve stem disposed within said strut,the lower end of said valve stem being adapted to Cooperate with saidvalve seat for regulating the flow of liquid from said storage chambertoprovide a selected rate of flow to said steam generator, and meansadjustably connecting said valve stem to the upper end of said strut,said valve stem and strut be- 10 ing in contact with the liquid storedin said chamber and being made of materials having substantiallydifferent coefficients of expansion and adapted upon a change intemperature of said strut and said valve stem to cause relative movementbetween said valve stem and said valve seat in the direction and in suchamount as to substantially reduce deviation from said selected rate offlow.

ELDRED O. MORTON.

